class Person14 {
  public readonly _name: string;
  constructor(public name: string) {
    this._name = name;
  }
}

const person14 = new Person14("tt1");
person14.name = "xx";
console.log(person14._name);

abstract class Girl14 {
  abstract skill(): void;
}

class Waiter14 extends Girl14 {
  skill(): void {
    console.log("waiter");
  }
}
class BaseTeacher14 extends Girl14 {
  skill(): void {
    console.log("Base");
  }
}
class SeniorTeacher14 extends Girl14 {
  skill(): void {
    console.log("Senior");
  }
}

const w1 = new Waiter14()
w1.skill();
